So, I’m preparing for a trip to Pimlico; to speak at a summit about public safety in abandoned quarries and a colleague quips, “that’s ironic, ‘cos there are no quarries in London”. He has a point, but it sets a deeper thought running.

Last time I went to Pimlico, I was there to visit Tate Britain. The treasures inside were all very well, but I was equally transfixed by the vast white elevation of building’s exterior – that Portland stone and its shrapnel marks, a testimony to a nearby instance of the Blitz: the smoothness of that surface ruptured by pock marks, revealing the granularity of the exposed quartz…